The question among N.T. scholars is whether the pistis Christou in Pauline literature should be rendered with the subjective genitive (ergo, “faithfulness of Christ”), OR the objective genitive (ergo, “faith in Christ”), e.g. Rom. 3:22, 3:36; Phil. 3:9.

Arguments in support of the subjective genitive (faithfulness of Christ):

  1. Rom. 3:3 refer to the faithfulness of God.
  2. Rom. 4:12 points to the faith of Abraham.
  3. The subjective use of the genitive feels most natural for this particular construction.
  4. Contextually in the subjective genitive, “faith in Christ” appear superfluous.
  5. “Faithfulness of Christ” refers to the obedience of Christ, which achieved salvation.
  6. “Faithfulness of Christ” fits with the coming event in salvation history.
  7. Paul’s theology focuses on the work of God in Christ, not human actions involving faith.

Arguments for the objective genitive (faith in Christ):

  1. The use of an objective genitive with “faith” is found in certain passages like Mark 11:22; James 2:1.
  2. The genitive can take an object, and this is grammatically normal.
  3. There is no absolute necessity for the subjective genitive.
  4. “Faith in Christ” is a simpler rendering, with the proper emphasis on Christ.
  5. “Faith in Christ” follows Paul’s dichotomy of “works of law” and “faith in Christ.”
  6. Paul does not use faith to describe obedience.
  7. Salvation history is poor argumentation, where anthropology dictates redemptive history.
  8. “Faith in Christ” is not Pelagian.

Source: Thomas Schreiner, New Testament Theology.